Automatic switch for storage batteries.



PATENTED AUG. 1, 1905. T. DUNCAN. AUTOMATIC SWITCH FOR STORAGE BATTERIES.

APPLIGATION FILED 31111.8,1902. RENEWED JAN.7,1905.

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Inventur: Thumasflunuart ACtu megs.

Witnesses;

THOMAS DUNCAN, OF LAFAYETTE, INDIANA.

AUTOMATIC SWITCH FOR STORAGE BATTERIES.

Specification of Letters Patent.

Patented Aug. 1, 1905.

Application filed January 8, 1902. Renewed January 7, 1905. $erial No. 239,984.

To (LZZ whom it TTZ/LI/Z/ concern:

Be it known that I, THOMAS DUNCAN, a citizen of the United States, residing at Lafayette, in the county of Tippecanoe and State of Indiana, have invented a certain new and useful Improvement in Storage Batteries, (Case No. 52,) of which the following is a full, clear, concise, and exact description, reference being had to the accom anying drawing, forming a part of this specification.

My invention relates to storage batteries,

and particularly to an improved means for automatically cutting the storage battery out of circuit with the charging source of current when the battery has been sufficiently charged.

The invention has for its object, first, the rovision of automatically-operated means for cutting the battery out of circuit; second, the provision of means for adjusting the operation of the cut-out mechanism to batteries of different capacities, and, third, the provision of means whereby the cut-out mechanism will not be operated upon a momentary full pressure of the battery secured before the battery has been fully charged. 1

At the present time in charging storage batteries it is the practice to connect them to a source of current and charge them until their electromotive force rises to a selected quantity, after which they are cut out of circuit by manually-operated switches, which require the constant attendance of one or more a potential-indicator having a contact set ata predetermined pressure and which serves when this pressure is reached to effect disconnection. The potential-switch is provided with a motor member having a pressurewinding connected across the charging-mains.

The motor is preferably in the form of a solenoid, the core of the solenoid carrying one terminal of the switch, the other terminal being adjustable to correspond with the selected pressure at which the circuit including the storage battery is to be opened. This pressure-motor preferably works in cooperation 4 with the potential-switch governed thereby,

the contacts of the switch constituting terminals of a releasing-magnet that efiects the separation between the storage battery and its charging-circuit. I do not Wish to be limited, however, in all embodiments of the invention to the precise agency acting in 006peration with the potential-motor for efiecting a separation between the storage battery and the charging-circuit.

As is well known to those skilled in the art,

the potential of the charging-circuit may.

under certain conditions fluctuate during the time of charge, and in order to prevent the potential-motor from effecting a premature separation between the storage battery and its charging-circuit upon the occasion of a fluctuation in the pressure that equals the predetermined pressure of the battery I employ a retarding agency that directly controls the release of the switch, but which requires a certain period of operation-say five minutesbefore it will effect the release of this switch, so that the switch cannot be released during the continuance of a momentary fluctuation in the pressure. The retarding agency is preferably in the form of a rotating motor, which may well be the motor of a voltmeter, which motor is preferably provided for the purpose with a train, one of the wheels whereof is equipped with a pin that operates a switch, which switch in turn may control the circuit including the releasing-magnet. An adjusting step-by-step resistance is included in circuit with the pressure-motor to vary the speed of its operation in accordance with the time that is to be allowed for insuring the completion of the charge. The releasing electromagnet is preferably associated with means whereby it may be directly controlled by the solenoid-motor independently of the rotating motor or directly by the rotating'motor acting in combination with the solenoid-motor.

I will explain my invention more fully by tact with the terminals 8 and 9 of the charging-circuit or the terminals 12 and 13 of the consumption-circuit to be supplied with en ergy from the storage battery. A circuitopening switch has its blade 14 and its contact 15 included in the main conductor 3. A detent 16 engages a catch 17, provided upon the blade to normally hold the blade in closed circuit, a spring 18 acting yieldingly to maintain this engagement. The detent is controlled by an electromagnet 19, whose armature may when attracted actuate the detent to release the blade 14, the armature for the purpose being preferably directly mounted upon the detent-lever. The winding of magnet 19 is connected in bridge of the mains 2 and 3, this bridge including either the branch conductor 20, the rotating pressure-motor 21 the movable contact 22, carried by the core 23 of the solenoid 24, the adjustable contact 25 when in engagement with the contact 22, or the branch conductor 26, the switch 27, and the conductor 28, according to the position. of the switch 29.

When the switch 29 is adjusted to include the magnet 19 in the bridge containing the conductor 20, although the motor 21 is in cluded in circuit, it is not included for any particular purpose, but merely constitutes a part of the bridge thus established, the apparatus in this adjustment being designed to immediately cut out the charging-machine from the storage battery when the contacts 22 and 25 are in engagement. When the switch 29, however, is adjusted to include the branches 26 and 28 in circuit, circuit through the magnet 1.9 cannot be closed until the switch 27 has been operated by the motor 21 to effect this closure. Assuming that the switch 29 is adjusted to include the conductor 20 in circuit, when the potential of the battery 10 is raised to the predetermined point the winding of the solenoid 24 will attract the solenoid-core until the conlever 16 is disengaged fro'mthe blade 141, and

the said blade is released from. its contact 15, thereby opening the circuit including the charging-machine 1. If, however, there should be a tendency to sudden fluctuations of potential, the switch 29 is adjusted to include the normally disconnected conductors 26 and 28, in circuit with the magnet 19, these conductors being connected by the switch 27 when the motor 21 has been operated a predetermined length of time.

of the said switch, the spring 31 upon thedisengagemcnt between the said switch and pin momentarily completing connection between the eonductors 26 and 28 to effect the energization of magnet 19 and the release of the switch-blade 14.

The contact engaged by the lever-switch, 27 is preferably arranged within the field of a magnet 341, included in the conductor 28, so that a magnetic blow-out may be established for disrupting the arcs. The switch 29 is preferably associated with a rheostat divided into a plurality of sections, so that the speed of the motor 21 may be adjusted ac cording to the time it is to operate before the switch 141: is opened.

There is included in the charging-circuit an ammeter 35 and a series resistance 36 for the purpose of regulating the volume of current that is being passed into the battery.

In order that the train maybe adjusted in (ilependently of the operation of the motor 21, as in resetting the train after the motor has once fully operated the same, the wheel 33 may be mounted upon a lever 1-37, pivoted at 38 and carrying the mounting of the wheel 33, a spring 39 yieldingly maintaining the wheel 33 in engagement with the balance of the train.

It is preferable that the speed of the motor 21 be constant for any pressure to which the adjustable contact 25 is set. To this end I: employ an armature 40, inductively arranged within the field produced by the coils 411 and the iron cord or keeper +12, so that the strength of the magnetic field will vary directly as the current through the armature 43 of the motor, whereby the desired constancy of speed with varying pressures is secured. The armature 13 and the winding 41 are preferably included in series and together included in bridge of the transmission-mains. The core portion 12 may be adjustable toward or from the disk to control the speed of the motor 2.] aside from the adjustment effected by the switch-arm 29. Other means may be employed for controlling the speed of this motor, if desired. The core 23- of the solenoid is preferably made to lit the bore of the solenoid snugly, while the bottom of the bore is closed to form an air dash-pot.

The expression pressure-motor herein relates to the primary agency 24, that effects supreme control over the electromagnet 11:),

, agency.

.The secondary electric motor is-styled the rotating pressure-motor 2-1 or retarding I do not wish to be limited to the forms that these motors take. In the claims .that follow the term pressure-motor is to be limited to the precise arrangement set forth; but,

Having thus described my invention, I

claim as new and desire to secure by Letters Patentl. The combination with a storage battery, of a charging-circuit for connection therewith, a switch for effecting disconnection between the storage battery and the charging source of current, motor means subject to the pressure and operating when the storage-battery pressure has reached a predetermined limit to operate the switch to disconnect the storage battery f-rom the charging-circuit, and a retarding agency cooperating with the said motor, means in effecting a disconnection of the storage battery but preventing premature disconnection, substantially as described.

2. The combination with a storage battery, of a charging-circuit for connection therewith, a switch for opening the chargingcircuit, an electromagnet for causing the switch to open, a pressure-motor for eflecting the operation of the electromagnet, and a retarding agency cooperating with the said motor in effecting a disconnection of the storage battery but preventing premature disconnection, substantially as described.

3. The combination with a storage bat tery, of a charging-circuit for connection therewith, a switch for opening the charging circuit, an electromagnet for causing the switch to open, a pressure-motor for effect ing the operation of the electromagnet, and a switch including the said electromagnet closed by the said motor upon the attainment of predetermined pressure, one of the contacts of the said switch being carried by the motor, the said contacts being relatively adjustable whereby the apparatus may be adjusted to effect disconnection of the storage battery with the charging-circuit at differing predetermined pressures, substantially as described.

4. The combination with a storage battery, of a charging-circuit for connection therewith, a switch for opening the chargingcircuit, an electromagnet for causing the switch to open, a pressure-motor for effecting the operation of the electromagnet, a second motor brought into action by the aforesaid motor, and a switch governed by the second motor for closing circuit through the said -electromagnet to effectdisconiiection be tween the storage battery and the charging circuit, substantially as described.

5. The combination with a storage battery, of a charging circuit for connection therewith, a switch for opening the charging-circuit, a pressure-motor, a second motor brought into action by the pressure-motor when a predetermined pressure has been attained, and means governed by the second motor for effecting the operation of the switch to disconnect the storage battery from the charging source of current, the second motor serving to retard the time of disconnection between the storage battery and the supply-circuit, substantially as described.

6. The combination with a storage battery, of a charging circuit for connection therewith, a switch for effecting disconnection between the charging-circuit and the storage battery, a potential motor, a second electric motor, a switch governed by the potential motor for closing circuit through the second motor, and means controlled by the second motor for effecting the operation of the first aforesaid switch to disconnect the storage battery from the charging-circuit, substantially as described.

7. The combination with a storage battery, of a charging circuit for connection therewith, a switch for effecting disconnection between the charging-circuit and the storage battery, a potential motor, a second electric motor, a switch governed by the potential motor for closing circuit through the second motor, means controlled by the second motor for effecting the operation of the first aforesaid switch to disconnect the storage battery from the charging-circuit, and means for varying the rate of speed of the second motor to adjust the delay in disconnection between the storage battery and the charging-circuit, substantially as described.

8. The combination with a storage bat tery, of a charging circuit for connection therewith, a switch for effecting disconnection between the charging-circuit and the storage battery, a potential motor, a second electric motor, a switch governed by the potential motor, for closing circuit through the second motor, and means controlled by the second motor for effecting the operation of' the first aforesaid switch to disconnect the storage battery from the charging-circuit,the second motor being provided with an armature and a braking electromagnet, both subject to the scribed.

9. The combination with a storage battery, of a charging circuit for connection therewith, a switch for effecting disconnection between the chargin circuit and the storage battery, a potentia motor, a second electric motor, a switch governed by the potential motor for closing circuit through the pressure, substantially as del second motor, means controlled by the second motor for efiecting the operation of the first aforesaid switch to disconnect the stor age battery from the charging-circuit, and an adjusting rheostat for varying the rate of operation of the second motor to adjust the delay in disconnection between the storage battery and the charging-circuit, substantially as described.

10. The combination with a storage battery of a charging circuit for connection therewith, a switch for opening the chargingcircuit, an electromagnet for causing the switch to open, electromagnetic means responsive to predetermined pressure for effecting the operation of the electromagnet, a switch operatively associated with the electromagnet, and a retarding agency for efi'ecting the operation of the said switch, substantially as described.

THOMAS DUNCAN. Witnesses:

SAMUEL R. BAcn'rnL, FRANK V. NELSON. 

